Effects of Construction of a Diaphragm Wall Very Close to a Masonry Building

Observations were made to study the settlement behavior of an old 4 story masonry building during the construction of a 25m deep diaphragm wall. The adjacent building, which was only 1.2m to 1.5m from the wall, was supported on shallow footings founded on weak deposits of loose sand and soft clay. A preliminary assessment before construction in the critical area indicated that settlement would be excessive if conventional construction procedures were followed. This led to the adoption of several settlement control measures in the construction process. It was found that these measures were effective in restricting the average settlement of the adjacent building to only 7.2mm and there was no visible sign of cracking.